Introduce FrameworkWidgetFactory

The framework uses a few QWidgets (FrameWidget, TabbarWidget, TabWidget
TitleBarWidget). This factory allows the user to provide his own,
to achieve different appearence.

src/FrameworkWidgetFactory.cpp

@@ -0,0 +1,57 @@
+/*
+  This file is part of KDDockWidgets.
+
+  Copyright (C) 2019 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
+  Author: Sérgio Martins <sergio.martins@kdab.com>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "FrameworkWidgetFactory.h"
+
+#include "widgets/FrameWidget_p.h"
+#include "widgets/TitleBarWidget_p.h"
+#include "widgets/TabBarWidget_p.h"
+#include "widgets/TabWidgetWidget_p.h"
+
+using namespace KDDockWidgets;
+
+FrameworkWidgetFactory::~FrameworkWidgetFactory()
+{
+}
+
+Frame *DefaultWidgetFactory::createFrame(QWidget *parent, Frame::Options options) const
+{
+    return new FrameWidget(parent, options);
+}
+
+TitleBar *DefaultWidgetFactory::createTitleBar(Frame *frame) const
+{
+    return new TitleBarWidget(frame);
+}
+
+TitleBar *DefaultWidgetFactory::createTitleBar(FloatingWindow *fw) const
+{
+    return new TitleBarWidget(fw);
+}
+
+TabBar *DefaultWidgetFactory::createTabBar(TabWidget *parent) const
+{
+    return new TabBarWidget(parent);
+}
+
+TabWidget *DefaultWidgetFactory::createTabWidget(QWidget *parent) const
+{
+    return new TabWidgetWidget(parent);
+}